Battery "system" advice for new sound system

Hey guys, I've been reading through some of the new and old "battery" threads and trying to get a handle on what I should be doing. Find myself getting more confused then when I started.

To recap, I'm installing a completely new WS system in my 2003 MC X2, to include 3 new amps which I approximate will total about 2500watts. Currently, I only have the one stock battery.

If you could please advise what I should do to upgrade this battery "system," that would be fabulous. I don't want to say that money is not an object, but I do have the cash to spend to make it right. I spend Sundays partying at the sandbar. Apparently, I need at least 1 or 2 batteries dedicated to the stereo, some sorta switch, and now I'm learning a charger (which I assume is for when I'm on the trailer).

Why do you need an onboard charging system? I have a regular 2A charger, is it good enough?

225 AH a piece so 450 total. Never been unhappy with mine.

Originally Posted by xaggie

225 AH a piece so 450 total. Never been unhappy with mine.

Don't you mean 900ah total if it's 4x225? Or am I missing something?

Am I right to think then that you guys with big battery banks lie the 450ah's worth of cart batteries rely entirely on onboard chargers and don't connect the batterys to the alternator?

I ask because I am installing a system that will draw 85amps but I only have a 65amp alt and single battery and don't want to fry the alternator!!

Matt, how much stereo are you running off those batteries and how much playing time are you getting with engine off?

Showmethebutter, my understanding and continuing education in these matters indicates that, yes, you should not rely on your alternator as it, even if upgraded, is ill equipped to keep up with actually charging batteries depleted from a serious stereo system.

Matt, using 6v batteries you have the equivalent power as a 12v with 225 aH, still probably plenty. I like golf cart batteries, they charge and maintain about 0.4v higher than AGMs, this translates into about 20% more playing time.

AH ratings are next to worthless when you are talking about audio applications, unless you are running a very small system (10-20 amp pull). AH testing is done at very low amperage draws for extended periods of time. You need to look at the instantaneous power output and the design of the battery. Thinner lead plates allow for more discharge faster and faster recharge times. Also the more plates you can pack into the battery the higher power output you will have, and extend the life of the battery with multiple discharge/recharge cycles.

Showmebutter/brian b: correct, you isolate this bank from your boat's starting/charging system. Rely on your onboard charger to recharge at the dock/house.

FYI, I had great success this weekend with the following strategy (you can see what batteries and stereo I'm running above):
Get to party cove and switch switch to "2", turn off boat
run in boat speakers only (syn1 and syn2) with sub gain down fairly low OR run tower speakers cranking, either/or for 30 minutes
run idle boat for 15 minutes
Repeat
The 2sum tower set up powered with 2 syn2's played loud all day like this.

I think it's mostly playing your system smarter not harder.

Originally Posted by brian_b

FYI, I had great success this weekend with the following strategy (you can see what batteries and stereo I'm running above):
Get to party cove and switch switch to "2", turn off boat
run in boat speakers only (syn1 and syn2) with sub gain down fairly low OR run tower speakers cranking, either/or for 30 minutes
run idle boat for 15 minutes
Repeat
The 2sum tower set up powered with 2 syn2's played loud all day like this.

I think it's mostly playing your system smarter not harder.

Brian, did you dealer ever get my email? Did you end up wiring the switch with the VSR the way I suggested?

If you did having the switch in position 2 means that you are draining down you starting battery and the stereo batteries. This may give you slightly more play time but you have the chance of running your start battery too low and not having enough juice to start. This will also will lead to shortened life of all electronics in the boat as well as the starter and alternator.

Hmmm...I don't know if he did actually change the wiring around. I am bringing the boat in tomorrow for some unrelated stuff, so I was going to discuss that tomorrow. Thanks for the heads up on that issue though.

He definetely got your email though, so did I. VERY helpful, as usual.

Presumptively my dealer knows where I should have my switch under your wiring scheme. I will review with him. He did not tell me to use "2', I just used that assuming the wiring was "original."

I will let you know...

batteries confuse me............ :S .... golf cart batteries are better..... no deep cycles are.... no way AGM is the best....... I have no clue what to do also

Pete (petrey10)
batteries confuse me............ :S .... golf cart batteries are better..... no deep cycles are.... no way AGM is the best....... I have no clue what to do also

I need batteries for my boat, and the more i read on this forum the more i get confused.

I guess i should be looking for golf kart batteries. Seems they have the highest AH rating for playing without the support of the alternator.

What is everyones opinion on the 4D batteries??

I agree with you Brian on using the stereo smarter instead of harder because I have to do this all the time in order to save battery power for the next day if the boat doesnt come off the water. How do most of you guys keep a seperate bank of batteries charged while the boat stays on the water for the weekend while your camping?

bump? Anybody on charging while camping?

I know alot of people are against Optimas, but here is my new triple Optima D31M setup (the Tray/Box was made here
http://www.optimatrays.com/index.php?body=custom_trays:

yeah man... someone says GC batteries another will say Wet Deep Cycle marine batteries.... other say spread 1500 bucks and get the best batteries.... I got no freaking clue!!!!!!!!!

I got 2 us2200 golf cart batteries. 232 amp-hours for 220$ to my door. I guess i can'T go wrong with that...

he's got 2 in pararell 2 in series. i beleive with the ones in series you don't add up the ah. but you double up the voltage.